A US federal judge has ordered the Food and Drug Administration to make "morning-after" emergency contraception pills available without a prescription to all girls of reproductive age.

Currently, only women aged 17 or older can obtain emergency contraception pills without a prescription in the US.

Point-of-sale restrictions require that all women present identification to a pharmacist before obtaining the drug.

In his ruling, US District Judge Edward Korman said the FDA's rejection of requests to remove age restrictions to obtain the pill was "arbitrary, capricious and unreasonable".

FDA spokeswoman Erica Jefferson declined to comment on the ruling, saying it was an ongoing legal matter.

The Center for Reproductive Rights and other groups had petitioned the FDA to strike down age and access limits on all emergency contraceptives.

They said there was no scientific proof that girls younger than 17 could not safely use the drug without supervision.

Teva Pharmaceuticals Ltd's Plan B in 1999 became the first emergency contraceptive available for prescription use in the US.

The company also markets Plan B One-Step, a one-pill version of Plan B.

Teva had also petitioned the government to allow sales of Plan B One-Step over the counter without restrictions.

In 2011, the FDA said it had concluded Plan B One-Step could be safely used in girls of child-bearing age.

But US Department of Health and Human Services Secretary Kathleen Sebelius, in an unprecedented move, overruled the FDA.

She said that there was insufficient evidence to support removing the restrictions.

Several days later, the FDA also rejected the petition to lower restrictions on all emergency contraceptives.

In today’s ruling, Judge Korman criticised the groups' justification for their decisions.

Judge Korman called it "an excuse to deprive the overwhelming majority of women of their rights to obtain contraceptives without unjustified and burdensome restrictions".